Detachable end effector and loader

ABSTRACT

A surgical device comprises an elongate shaft having an outer tube and an inner rod positioned in the outer tube. The outer tube and inner rod each comprise a distal end and a proximal end. An actuator is operably connected to the proximal ends of the outer tube and the inner rod. An end effector is adapted for in vivo attachment to and detachment from the elongate shaft. The end effector comprises an outer casing comprising a first detent mating feature adapted to engage the distal end of the outer tube; an inner shuttle axially moveable relative the outer casing, the shuttle comprising a second detent mating feature adapted to engage the distal end of the inner rod; and a pair of surgical jaws having an opened position and closed position dependant on the relative axial position of the shuttle and casing. A tubular loader is sized to receive the end effector, the tubular loader comprising third detent mating feature adapted engage end effector.

BACKGROUND

The present invention relates in general to surgical devices andprocedures, and more particularly to minimally invasive surgery.

Surgical procedures are often used to treat and cure a wide range ofdiseases, conditions, and injuries. Surgery often requires access tointernal tissue through open surgical procedures or endoscopic surgicalprocedures. The term “endoscopic” refers to all types of minimallyinvasive surgical procedures including laparoscopic, arthroscopic,natural orifice intraluminal, and natural orifice transluminalprocedures. Endoscopic surgery has numerous advantages compared totraditional open surgical procedures, including reduced trauma, fasterrecovery, reduced risk of infection, and reduced scarring. Endoscopicsurgery is often performed with an insufflatory fluid present within thebody cavity, such as carbon dioxide or saline, to provide adequate spaceto perform the intended surgical procedures. The insufflated cavity isgenerally under pressure and is sometimes referred to as being in astate of pneumoperitoneum. Surgical access devices are often used tofacilitate surgical manipulation of internal tissue while maintainingpneumoperitoneum. For example, trocars are often used to provide a portthrough which endoscopic surgical instruments are passed. Trocarsgenerally have an instrument seal, which prevents the insufflatory fluidfrom escaping while an instrument is positioned in the trocar.

While a variety of different minimally invasive surgical devices areknown, no one has previously made or used the surgical devices andmethods in accordance with the present invention.

SUMMARY

In one embodiment, a surgical device comprises an elongate shaft havingan outer tube and an inner rod positioned in the outer tube. The outertube and inner rod each comprise a distal end and a proximal end. Anactuator is operably connected to the proximal ends of the outer tubeand the inner rod. An end effector is adapted for in vivo attachment toand detachment from the elongate shaft. The end effector comprises anouter casing comprising a first detent mating feature adapted to engagethe distal end of the outer tube; an inner shuttle axially moveablerelative the outer casing, the shuttle comprising a second detent matingfeature adapted to engage the distal end of the inner rod; and a pair ofsurgical jaws having an opened position and closed position dependant onthe relative axial position of the shuttle and casing. A tubular loaderis sized to receive the end effector, the tubular loader comprisingthird detent mating feature adapted engage end effector.

The first, second, and third detent mating features may have a thresholddisengagement force F₁, F₂, and F₃, respectively, of the followingrelative magnitudes: F₁<F₃<F₂. The first detent mating feature maycomprise a leaf spring on the outer casing adapted to engage a notch onthe outer tube. The third detent mating feature may comprise a leafspring on the tubular loader adapted to engage a notch on the outercasing. The second detent mating feature may comprise a pair ofproximally oriented prongs, each having a medially oriented toothadapted to engage a notch on the inner rod. The distal end of the outertube may comprise a sloped surface adapted to engage and laterallyspread the prongs thereby disengaging the teeth from the notch on theinner rod.

In another embodiment, a surgical device comprises an elongate shaftcomprising an outer tube and an inner rod positioned in the outer tube,the outer tube and inner rod each comprising a distal end and a proximalend. An actuator is operably connected to the proximal ends of the outertube and the inner rod. An end effector is adapted for in vivoattachment to and detachment from the elongate shaft. The end effectorcomprises an outer casing comprising a first mating feature adapted toengage the distal end of the outer tube; an inner shuttle axiallymoveable relative the outer casing, the shuttle comprising a secondmating feature adapted to engage the distal end of the inner rod; and apair of surgical jaws having an opened position and closed positiondependant on the relative axial position of the shuttle and casing. Thesecond mating feature comprises a pair of proximally oriented prongs,each having a medially oriented tooth adapted to engage a notch on theinner rod. The distal end of the outer tube comprises a sloped surfaceadapted to engage and laterally spread the prongs thereby disengagingthe teeth from the notch on the inner rod. The first mating feature maycomprise a detent mechanism.

In yet another embodiment, a surgical device comprises an elongate shaftcomprising an outer tube and an inner rod positioned in the outer tube,the outer tube and inner rod each comprising a distal end and a proximalend. An actuator is operably connected to the proximal ends of the outertube and the inner rod. An end effector is adapted for in vivoattachment to and detachment from the elongate shaft. The end effectorcomprises an outer casing and a means to attach the outer casing to theouter tube; an inner shuttle axially moveable relative the outer casingand a means to attach the shuttle to the inner rod; and a pair ofsurgical jaws having an opened position and closed position dependant onthe relative axial position of the shuttle and casing. A tubular loaderis sized to receive the end effector and includes a means to attach theend effector in the tubular loader.

BRIEF DESCRIPTION OF DRAWINGS

While the specification concludes with claims which particularly pointout and distinctly claim the invention, it is believed the inventionwill be better understood from the following description taken inconjunction with the accompanying drawings illustrating somenon-limiting examples of the invention. Unless otherwise indicated, thefigures are not necessarily drawn to scale, but rather to illustrate theprinciples of the invention.

FIG. 1 depicts an example of a loader, end effector, shaft, andactuator;

FIG. 2 depicts an exploded view of the shaft;

FIG. 3 depicts a cross-sectional view of a portion of the shaft;

FIG. 4 depicts a perspective view of the end effector;

FIG. 5 depicts an exploded view of the end effector;

FIG. 6 depicts a side view of the loader and end effector;

FIG. 7 depicts a cross-sectional view of the end effector locked in theloader; and

FIG. 8 depicts a cross-sectional view of the end effector attached tothe shaft and unlocked in the loader.

DETAILED DESCRIPTION

The figures illustrate one example a laparoscopic surgical instrumentsystem. The elongate shaft (20) comprises an outer tube (23) and aninner rod (24) positioned in the outer tube (23). The elongate shaftcomprises a distal end (21) and a proximal end (22). The elongate shaft(20) may be rigid and adapted for insertion into a body cavity throughan access device, such a trocar, or through direct percutaneousinsertion without an access device. The elongate shaft (20) may also beflexible and sized for insertion through the working channel of aflexible endoscope. The rigid shaft embodiment is well suited forlaparoscopic surgical procedures, and the flexible shaft embodiment iswell suited for natural orifice intraluminal and natural orificetransluminal procedures.

An actuator (30) is operably connected to the proximal ends (22) of theouter tube (23) and the inner rod (24). The actuator (30) causes theinner rod (24) to move relative the outer tube (23). In this embodimentthe actuator (30) is a manual pistol grip handle; however, a variety ofother manual actuators could also be used, including a scissor griphandle, a syringe grip handle, endoscopic rotary knobs, and the like.The actuator (30) could also take the form of a robotic interface, suchas an DAVINCI puck, a housing comprising gears or pulleys,servomechanisms, and the like.

The end effector (10) is adapted for in vivo attachment to anddetachment from the elongate shaft (20). An inner shuttle (14) isaxially moveable relative the outer casing (12). The shuttle comprises amating feature adapted to attach to the distal end of the inner rod(24). The specific mating feature can vary, but in this embodiment themating feature comprises a detent-type mechanism comprising a pair ofproximally oriented prongs (14A), each functioning as leaf spring tobias a medially oriented tooth (14B) to engage the notch (27B) on theinner rod (24).

A pair of surgical jaws (11A, B) have an opened position and closedposition dependant on the relative axial position of the shuttle (14)and the outer casing (12). A clevis (15) is fixed to the outer casing(12). A bar linkage mechanism (13) cooperates with the clevis (15) totranslate the axial motion of the shuttle (14) to open and close thejaws (11); however, a variety of other known mechanisms can be used toeffect operation of the jaws (11). In this embodiment, the jaws (11) areshown as a grasper; however, a variety of other tissue manipulating jawscould also be used, including dissectors, sheers, babcocks, forceps,staplers, clip appliers, and the like. Non-jawed end effectors couldalso be employed such as hook knives, snares, retractors, and the like.In the case of end effectors that require energy, appropriate energytransmission mechanisms known in the art can be added. For instance,appropriate electrical connections can be added between the shaft (20)and end effector (10) to enable bi-polar forceps. Similarly, anultrasonic transducer and waveguide can be added for the ultrasonicshears end effector.

The end effector (10) comprises a mating feature (17) adapted to attachthe outer casing (12) to the outer tube (23). In this embodiment themating feature (17) is a detent-type mechanism comprising two leafsprings, positioned 180 degrees from each other on the outer casing(12), each having a medial facing tooth. As the outer tube (23) slidesdistally into the outer casing (12), and the leaf springs provide abiased snap-to-lock engagement of the teeth into the notch (27A). Othermating features could also be used, including threads, collets,bayonets, and the like. Keyway features (19) are sized and adapted toengage the spline features (28) on the outer tube (23) to facilitaterotational coupling when the outer tube (23) is attached to the outercasing (12).

A loader (40) comprises a handle (45), a shaft (43), and a distal tube(41) that may articulate relative the shaft (43). The tube (41) is sizedto receive the end effector (10). The tube (41) comprises a matingfeature (42) adapted to attach the end effector (10) inside the tube(41). In this embodiment the mating feature (42) is a detent-typemechanism comprising two leaf springs, positioned 180 degrees from eachother on the tube (41), each having a medial facing tooth. As the endeffector (10) slides into the tube (41), and the leaf springs provide abiased snap-to-lock engagement of the teeth into the notch (18). Othermating features could also be used, including threads, collets,bayonets, and the like.

The three mating features (17, 14A, and 42) each have a threshold axialforce that will cause the respective components to disengage. Forinstance, the threshold disengagement force of the mating feature (17)is the axial force required to separate the outer housing (12) from theouter tube (23). Preferably, the relative magnitudes of the thresholddisengagement forces are in accordance with the following equation:F₁<F₃<F₂

where

-   -   F₁ is the threshold disengagement force between the outer        housing (12) and the outer tube (23);    -   F₂ is the threshold disengagement force between the shuttle (14)        and inner rod (24);    -   F₃ is the threshold disengagement force between the loader tube        (41) and the end effector (10);        During surgery, the distal end (21) of the shaft (20) is        inserted into the body cavity, such as the abdomen, pelvis,        thorax, etc. The end effector (10) is attached into the tube        (41) and also introduced into the body cavity, typically through        an access port. The loader tube (41) can be articulated to        facilitate bringing the end effector (10) into axial alignment        with the shaft (20). The distal end (21) is then inserted into        the end effector (10). The outer tube (23) slides distally into        the outer casing (12) until the leaf springs of the mating        feature (17) provide a biased snap-to-lock engagement into the        notch (27A), thus attaching the outer casing (12) to the outer        tube (23). The inner rod (24) slides distally into the shuttle        (14) until the prongs (14A) provide a biased snap-to-lock        engagement with the teeth (14B) into the notch (27B), thus        attaching the shuttle (14) to the inner rod (24). The end        effector (10) is now fully attached in vivo to the shaft (20)        and can then be pulled from the tube (41). Because F₂>F₁,        pulling the shaft (20) proximally will cause the end effector        (10) to be pulled out the loader tube (41). The loader (40) can        be removed from the surgical field. Operation of the actuator        (30) translates to operate the jaws (11), thus enabling a        surgeon to manipulate tissue and perform minimally invasive        surgical procedures.

In vivo detachment is achieved by reversing the attachment stepsoutlined in the previous paragraph. The loader (40) is introduced intothe body cavity and the end effector (10) is slid into the tube (41).The distal end (21) of the outer tube (23) comprises a sloped surface(29). When the slider (25) is advanced distally and compresses thespring (26), the sloped surface (29) also advances distally to engageand laterally spread the shuttle prongs (14A) thus disengaging the teeth(14B) from the notch (27B) on the inner rod (24). The pin (25A) slidesin L-shaped slot, enabling the surgeon to keep the sloped surface (29)in its distal-most position. The inner rod (24) can now be pulled fromthe shuttle (14), effectively making F₂ equal to zero (the slopedsurfaces (29) may also be used to facilitate in vivo insertion of theinner rod (24) into the shuttle (14)). Because F₃>F₂, pulling the shaft(20) proximally will cause the end effector (10) to detach from theinner rod (24) leaving the end effector (10) attached inside the loadertube (41).

Having shown and described various embodiments and examples of thepresent invention, further adaptations of the methods and devicesdescribed herein can be accomplished by appropriate modifications by oneof ordinary skill in the art without departing from the scope of thepresent invention. Several of such potential modifications have beenmentioned, and others will be apparent to those skilled in the art. Forinstance, the specific materials, dimensions, and the scale of drawingswill be understood to be non-limiting examples. Accordingly, the scopeof the present invention should be considered in terms of the followingclaims and is understood not to be limited to the details of structure,materials, or acts shown and described in the specification anddrawings.

The invention claimed is:
 1. A surgical device, comprising: a) anelongate shaft comprising an outer tube and an inner rod positioned inthe outer tube, the outer tube and inner rod each comprising a distalend and a proximal end; b) an actuator operably connected to theproximal ends of the outer tube and the inner rod; c) an end effectoradapted for in vivo attachment to and detachment from the elongateshaft, the end effector comprising: i) an outer casing comprising afirst detent mating feature adapted to engage the distal end of theouter tube; ii) an inner shuttle axially moveable relative the outercasing, the shuttle comprising a second detent mating feature adapted toengage the distal end of the inner rod; iii) a pair of surgical jawshaving an opened position and closed position dependant on the relativeaxial position of the shuttle and casing; d) a tubular loader sized toreceive the end effector, the tubular loader comprising third detentmating feature adapted engage end effector; wherein the first, second,and third detent mating features have a threshold disengagement forceF1, F2, and F3, respectively, of the following relative magnitudes:F1<F3<F2.
 2. The surgical device of claim 1, wherein the first detentmating feature comprises a leaf spring on the outer casing adapted toengage a notch on the outer tube.
 3. The surgical device of claim 1,wherein the third detent mating feature comprises a leaf spring on thetubular loader adapted to engage a notch on the outer casing.
 4. Asurgical device, comprising: a) an elongate shaft comprising an outertube and an inner rod positioned in the outer tube, the outer tube andinner rod each comprising a distal end and a proximal end; b) anactuator operably connected to the proximal ends of the outer tube andthe inner rod; c) an end effector adapted for in vivo attachment to anddetachment from the elongate shaft, the end effector comprising: i) anouter casing and a means to attach the outer casing to the outer tube;ii) an inner shuttle axially moveable relative the outer casing and ameans to attach the shuttle to the inner rod; iii) a pair of surgicaljaws having an opened position and closed position dependant on therelative axial position of the shuttle and casing; d) a tubular loadersized to receive the end effector and a means to attach the end effectorin the tubular loader; wherein the means to attach the outer casing tothe outer tube has threshold disengagement force F1, the means to attachthe shuttle to the inner rod has threshold disengagement force F2, andthe means to attach the end effector in the tubular loader has thresholddisengagement force F3, and wherein F1<F3<F2.